The present invention relates to a method of making a multipurpose clamping device designed for holding objects while preventing damage thereto, such a device and its use.
Among the clamping tools including two jaws, of which one can slide along a straight guide piece, some of them are totally lacking forcible pressing means, such as screws, eccentrics, springs, hydraulic means or the like. Thus Ralph K. Coffman has filed in 1945 a patent application to get the U.S. Pat. No. 2,510,077 which discloses such a tool Coffman""s tool is characterized in that said guide piece comprises several (three on the drawings) parallel and distinct cylindrical rods distributed along the jaws depth, and said jaws are equipped at one of their ends with cork pads facing each other. On the other hand, small bars at each of their ends laterally link the rods to each other, the central rod being tied to these small bars. Therefore said jaws are kept imprisoned between these said small end bars. It seems that Coffman was utterly convinced that could the jaws lock by friction on the guide piece, should this guide include several rods and these rods be automatically bent for clamping. Consequently could the jaws be parallel to each other for clamping, should these ones be leaning towards each other at rest, on the cork pads side, by an acute angle.
No more he seemed to be familiar with the clamp for dxc3xa9cor molding, called xe2x80x9cpresse-marteauxe2x80x9d or xe2x80x9chammer-pressxe2x80x9d, such it has been disclosed page 107, FIG. 257, in Lombard and Masviel""s book, entitled xe2x80x9cCours de Technologiexe2x80x9d Band 1 (for wood) and published by Dunod and Pinat in 1907in Paris. This xe2x80x9chammer-pressxe2x80x9d which belongs to the kind of clamping tools mentioned at the beginning of this prior art review also locks by friction, but its guide piece comprises only one rod and its jaws are essentially parallel to each other at rest. This xe2x80x9chammer-pressxe2x80x9d is also found, always offered made of wood (generally of hornbeam wood), in many commercial hardware catalogs. For example, it can be found in the 1910 catalog of xe2x80x9cCharbonnel et Filsxe2x80x9d based in Thiviers, Dordogne, France FIG. 378 of 40th plate). It can be also found in the 1924 catalog of xe2x80x9cEtablissements F. Guitel and Etienne rxc3xa9unisxe2x80x9d based in Saint-Martin street in Paris (see FIG. 2592 nof page 232). It can be as well found in the 1927 catalog of the xe2x80x9cForge Royalexe2x80x9d based in Faubourg Saint-Martin street in Paris (see FIG. 306 of 32nd plate). In these catalogs, the hammer-press is presented with a guide piece comprising only one cylindrical rod and with one of the jaws fixed at one end of said rod. In addition in these catalogs, the jaws of the hammer-press are shown without any pad, made of cork or something else. But said jaws are equipped at their farthest end from the rod in front of the other jaw with a place, where a pad could be precisely bonded on. And in 1948, the same xe2x80x9chammer-pressxe2x80x9d is shown (see pages 27 Fillet and Combe based in Bourgouin (Isxc3xa8re, France). Henri Trillat has become familiar with the xe2x80x9chammer-pressxe2x80x9d equipped with cork pads, before becoming teacher of technical education in 1932, as he was an employee in cabinetmaking workshops (as a foreman for furniture manufacturing, at the end). Therefore, he has taught this clamp to his students from 1932. Numerous xe2x80x9chammer-pressesxe2x80x9d with cork pads can be found in old cabinetmaking workshops in France. A distinctive feature of the xe2x80x9chammer-pressxe2x80x9d, such as it is represented in Trillat""s book, is that the straight rod supporting the jaws is circular, whereas in the aforementioned commercial catalogues, the rod is systematically shown with a rectangular section. And this xe2x80x9chammer-pressxe2x80x9d is hand clamped, as Trillat states it page 83, this time in sight of figure 31 of a revision of his first work, entitled xe2x80x9cTechnologie Gxc3xa9nxc3xa9rale et de Spxc3xa9cialitxc3xa9 en Menuiserie Ebxc3xa9nisteriexe2x80x9d (xe2x80x9cGeneral and Special Technology for Joinery and Cabinetwork) and published by Dunod, Paris, in 1959. This xe2x80x9chammer-pressxe2x80x9d can be quite compared to the clamps that have been disclosed later on in the patent applications filed by Ditto in May 1981 (to get the U.S. Pat. No. 4,555,100 ) and fled by Pappas in November 1984 (PCTIUS85/00420 application). The only exception is that the guide piece in Ditto and in Pappas appears to be parted in two parallel straight rods. Pappas considers however, at the two thirds of the page 3 of his application, that the guide piece of the jaws might be made up of only one rod. Both are claiming a clamping tool comprising two jaws and a straight guide piece. One of said jaws is fixed to one end of said guide piece. The other jaw can run along said guide piece parallel to said first jaw and remaining parallel thereto at rest. Each of said two jaws is provided at a distance from said guide piece, as it is for Trillat""s xe2x80x9chammer-pressxe2x80x9d, with an elastic cork-type pad facing the other jaw.
The present invention is distinct from the prior art evoked before in what it consists in replacing by a substantially elastic buffer any cork pad such as the one which can be found on a jaw of Trillat""s xe2x80x9chammer-pressxe2x80x9d.
Therefore, the new clamp can conform to difficult shapes unlike what cannot do prior art clamps like the one of Coffman, or like the xe2x80x9chammer-pressxe2x80x9d. Thus, a clamping device equipped according to the present invention comprises:
a cylindrical support part, such as a rod or a tube, with a section circular or not, and
two arms each arm including a transverse hole and at least one of these arms carrying an elastic buffer secured thereto, said buffer having a contact face for contacting any object to be clamped and having under its contact face a thickness large enough so that said buffer acts as a compression spring when said buffer contacts said object, and being resilient enough such that said contact face can flex and pivot to substantially conform to the surface of said object. Said support part is disposed within said transverse holes of said arms such that at least one of said arms is movable along said support part. And said buffer is disposed at a distance from said support part with its contact face approximately at a right angle to said support part.
One at least of said two arms being movable means that one arm (the other one) might be fixed But in combination to the replacement of cork pads by substantially elastic buffers, the two arms can be selected both movable along said support and fit for being easily slipped outwards thereof and inwards again. That gives the xe2x80x9chammer-pressxe2x80x9d new and considerable possibilities and turns said press into a versatile tool Indeed not only the new xe2x80x9chammer-press xe2x80x9d according to the present invention can be used as a clamp conforming to difficult shapes, but also, when the arms are reversed on the support part, as a spreader to press against a nook sides. And when said arms are moreover fit to be turned around it into at least two directions and other such arms are added on same support part, one gets an overlapping clamp, which is a new kind of clamp with four arms providing a spectacularly sturdy and stable clamping. And with other pairs of arms added on said support part that gives various types of ample multiple helping hands. By joining two support parts end to end with a coupler of the electrical connector type and by positioning at least one of the arms on each of said two support parts, the maximum opening is considerably extended. Such connectors, when they are multiple, make possible a parallel coupling of the rods to build multi-contact vices or to perform multidirectional clamping by bending electrical connector bars (of which the coating is usually make out of a supple plastic material). Therefore a device according to the invention can be obtained by the global method comprising the following steps of:
providing a cylindrical support part, such as a rod or a tube, with a section circular or not,
providing two arms, each arm including a transverse hole and at least one of these arms carrying an elastic buffer secured thereto, said buffer having a contact face for contacting any object to be clamped and having under its contact face a thickness large enough so that said buffer acts as a compression spring when said buffer contacts said object, and being resilient enough such that said contact face can flex and pivot to substantially conform to the surface of said object, and
placing said arms on said support part such that said support part is disposed in said transverse holes of said two arms and at least one arm is movable along said support part, and said buffer is disposed at a distance from said support part with its contact face approximately at a right angle to said support part.
The present invention can further be distinguished from the prior art evoked before when said substantially elastic buffers replacing the traditional cork pads are ring buffers elastic on all sides, but with a greater thickness under the contact face. There are numerous advantages of ring buffers over cork pads. First of all, there is no more need for a fastening system, such as a sticking, such as a pin and a hole, to secure the pad or buffer to the jaw. Additionally, the ring buffers can receive and support laterally other buffers fitting out others jaws, thereby enabling and facilitating all angular directions of clamping, whatever is the outline shape of the parts to be clamped. And of course, the ring buffers are easily interchangeable with differently contoured ring buffers, to seize for example pieces difficult of access. Thornton (U.S. Pat. No. 4,834,352 ) thought for his handle-equipped clamping device of totally surrounding the jaw ends with safety pads having an uniform and slight (see Thornton p.4, lines 16-17) thickness. Clearly in view of their slight thickness, the purpose of these pads was to act as protecting wedges, but not as an essential means for exerting a pressure during clamping, let alone conforming to difficult shapes. The pressure means is materialized in Thornton by a big pin xe2x80x94shaped spring. In the present invention, the ring buffers are constituting the pressure means for the clamping and consistently they are thicker in the clamping direction which makes possible in addition of conforming to difficult shapes. That is in what the ring buffers are differing from the safety pads of Thornton. The difference is all the more marked since Thornton""s device is clearly departing from the xe2x80x9chammer-pressxe2x80x9d concept. It is more like a clothes peg extrapolation towards a large opening with the traditional defects of the clothes peg: jaws diverging from parallel during the clamping operation and force nearly impossible to be controlled because of the lever effect. The use of safety pads, which is otherwise classic (around pliers noses or around fingers with gloves), is not liable to fundamentally alter the performances of the clothes peg. On the contrary, the use of ring buffers, as pads, for the xe2x80x9chammer-pressxe2x80x9d, gives thereto new properties. For example, there is the possibility in conjunction with another xe2x80x9chammer-pressxe2x80x9d according to the present invention, of clamping in all angular directions with an automatic control of the clamping force. That would be rather difficult if not impossible with Thornton""s press.
nSo as said at least two movable and removable arms be easily slipped outwards of said support part and inwards again, the support part ends might be equipped with removable stops. Said removable stops might be of the type clips, riders, pins, keys, or sections of cylindrical supple sheath slipped on by a gentle forcing.
A device according to the present invention will be called an assembler for the rest of the description.
The clamping of an object with an assembler, comprising only two arms, consists in
positioning said object between said arms,
sliding said at least one movable arm along said support part so as to apply the contact face of said elastic buffer against a respective surface of said object,
manually exerting pressure upon the backs of said arms in direction of said object. The force exerted by fingers or hand palms on said backs is more or less transmitted by translation against said object. This object reacts and opposes a resistance, which rises with the exerted pressure and
stopping the exertion of pressure when hands feel enough resistance. Said at least one movable arm is then repulsed by said object. As a result, it tilts with respect to said support part, such that a frictional force is created between said support part and an interior surface of the transverse hole of said arm, thereby locking said arm in place with respect to said support part. When said object is replaced by nothing between said arms, same maneuver also results into locking said at least one movable arm in place with respect to said support part by tilting. Each of said arms repulses the other one.
Spreading between two surfaces is performed according to the same principle: the arms being reversed along the support part, pushing is made in the opposite direction. The clamping operation is the same when the support part is split up into several cylindrical parallel components, distributed not along the arms unlike in Coffman, Ditto or Pappas, but at a right angle to said arms.
The clamping operation is somewhat different in the approach of the movable arms when the following conditions are met:
(i) the assembler just comprises four movable arms which can be turned in two directions V-diverging about said support part,
(ii) said arms are fitted out with elastic buffers,
(iii) the buffers of the first two arms along said support part have their contact faces facing towards a first direction and the contact faces of the buffers of the two following arms are facing towards a second direction opposite the first one. The two first arms are V-diverging around said support part and are pushed towards the following ones, more or less positioned according to same V. Roughly the first arm buffer is facing towards the third arm buffer while the second arm buffer is facing towards the fourth arm one. But the locking principle remains the same. As soon as the buffer contact come into contact with the surfaces of the object to be clamped, the force exerted by fingers or hand palms on said first arms is more or less transmitted by translation against said object. This object reacts and opposes a resistance, which rises with the exerted pressure. Exerting of pressure can be stopped when hands feel enough resistance. Said movable arms are then repulsed by said object As a result, they tilt with respect to said support part, such that a frictional force is created between said support part and the interior surface of the transverse hole of said arms, thereby locking them in place with respect to said support part. Such a clamping operation has been called xe2x80x9coverlappingxe2x80x9d and such an assembly of four movable arms on a cylindrical support part has been called xe2x80x9coverlapperxe2x80x9d or xe2x80x9csuper-assemblerxe2x80x9d.
The overlapping can be used as well for spreading. The operation is the same except those arms are reversed along the support part. A configuration halfway between a single assembler and an overlapper or super-assembler according to the present invention can be obtained by using two movable arms V-diverging facing a single third one for the clamping. Depending on the relief of the surfaces to be held, such a configuration might be sufficient.
With the overlapping which offers four contact faces, one can notice a spectacularly more vigorous and stable clamping than with an assembler comprising only two movable arms, even upon tortured patterns. When an overlapper is clamping a small wood plaque upon a table edge with about 60xc2x0 as an angle for the V formed either by the first arms or by the following ones, it is extremely difficult to detach said wood plaque from the table. And however each movable arm only underwent the thrust of one finger extremity during the clamping operation. To perform such a detaching, one hand grasping the small wood plaque with all fingers and drawn itself by a human arm of medium strength is insufficient. On the other hand, it appears that it is quite possible to carry out a stable and efficient clamping even if the four buffers are pressing by their contact face at different levels upon a tortured relief. Such a possibility is of course extremely practical for the restoration of gilded artifacts such as frames and cartouches. With the sub-variant of the overlapper comprising only three arms, two first ones forming a V and a third one pressing more or less in front of the middle of the V, one can avoid obstacles which prevent from clamping oppositely. Thus when the buffers of said movable parts forming the V press the pedestal of a clock on both sides of a column, the buffer of the opposite movable arm can press against the pedestal afoot opposite the column.
If a third pair of movable arms fitted out with such buffers is added onto a bare portion of the support part of an overlapper, one gets a helping-hand. When the overlapper grasps the lateral edge of an horizontal bench or table, said third pair can hold some objects to be painted or to be worked with free hands. This helping hand is called a three-element vertical helping-hand. If to this third pair of movable arms, called a holder, is added a fourth, a fifth, etc. pair of movable arms, still placed on a bare portion of the support part, one gets successively one four-element, one five-element, etc. vertical helping hand. When each of the added pairs of movable parts, also called holders, can be turned in several directions around said support part, these auxiliary hands are even more practical.
One can get another configuration of auxiliary hands by placing along said support part, one behind the other, three pairs of movable arms fitted out with substantially elastic buffers, said buffers facing each other by their respective contact face for each pair. At one end of the support part, the two first pairs of movable arms are separately locked by clamping with each buffer having its contact face against the contact face of the other buffer at an angle not equal to zero but possibly markedly upper or lower than 90xc2x0. Along the remaining portion of the support part, the third pair of movable arms also constitutes a holder to hold objects to be painted or to be worked on with free hands. The so-built helping-hand is called for the remainder of the present specification a three-element horizontal helping-hand. It can be installed anywhere on a more or less horizontal surface because it rests on three feet: the sets of the buffers of the first two pairs of movable arms locked at one end of the support part and the other end of the last one. If to this third pair is added a fourth, a fifth, etc. pair of movable arms, still placed on the remaining portion of the support part, one gets successively one four-element, one five-element, etc. horizontal helping-hand. Nota bene: So that one of the above-mentioned helping hands could keep objects in position firmer, one overlapper can replace one holder. The interest of the just above described helping hands as compared with the traditional helping-hands lies in different aspects:
Firstly, the holders that are equipping the helping hands according to the invention cannot with their elastic buffers scratch held pieces as the crocodile clips of the traditional helping hands can do with their teeth.
Secondly, unlike crocodile clips these holders are provided with jaw members which can open very widely while remaining parallel to each other.
Lastly, the helping hands according to the invention are distinctly lighter than the traditional helping hands since they do not require a heavy pedestal to keep standing, even when the holders are loaded. Four of the movable arms that are placed along the support part are sufficient to steady the basis of such kinds of helping-hands (see above). That just shows the generic power of the combination: cylindrical support part, movable arms and substantially elastic buffers.
Of course, configurations as the overlapper and the vertical and horizontal helping hands can only be built because of the possibility for the movable arms to be turned in more than one direction around the support part.
The modularity of the assemblers, which derives from the movability of the arms along the cylindrical support part, is creating a faculty not available up to now with the clamping tools: increasing at will the maximum opening. Said arms can be slipped outwards of their support part (the possible stops at ends thereof are removable) and slipped onto another support part of same section. Cylindrical support parts can be fixed end to end by couplers such as electrical connecting devices, muffs for mechanical pipes or cable links. It matters little that the couplers are barriers against the mobility of the arms between the different support parts. Placing one movable part on each of the two most extreme portions of said support parts is sufficient and the maximum opening between the two so used movable arms is inevitably larger than it would be if these two arms would be placed on only one of these support parts. In this manner the maximum opening according to the invention easily becomes extensible, which contrasts sharply with the traditional clamps where the extension of the support part is not permitted. Naturally, if not one but several movable parts are placed on each of the two most extreme portions of the support parts so connected end to end, it is possible to give a considerable maximum opening to all above disclosed original variants of the invention, as the overlapper and the new kinds of helping hands, etc. On the other hand, it can be also contemplated extending a support part with support parts having a different section by couplers the inlets of which being fit for different diameters. In this way movable arms having different dimensions could be faced to each other. Depending upon the shape of the objects to be clamped, such an arrangement dimensions could be very helpful. Connecting devices for big section electrical wires can provide couplers with inlets fit for different diameters.
According to a somewhat similar arrangement, denominated xe2x80x9cradial clampingxe2x80x9d on the support part of an assembler including a minimum of two movable arms is secured a coupler. This coupler is fit to seize, in at least one direction distinct from said support part direction another support part which can carry a minimum of one movable arm provided with an elastic buffer. Such a coupler is possibly made of a crosspiece like those which are used in electricity as a shunt contact or those which are used in the Navy or in xe2x80x9cMecanoxe2x80x9d building set to secure the crossing of two cables or halyards. It might also consist of a little bar of electrical connecting devices which is kept bent for example by the way it is secured to the first of said support parts. If this support part and another of said ones are at an angle of about 90xc2x0, it is possible to clamp things by three sides (T clamping) or by four sides (cross clamping). And when the coupler can hold several support parts in directions all distinct from the direction of the support part upon which the coupler is secured, it is possible to clamp things by numerous sides between the movable arms which are carried by said support parts. Such a way of clamping is then called a radial clamping. Of course said ways of clamping, the T one, the cross one and the radial one, can be operated with movable parts combined in over lappers. With the radial clamping, it is possible of pulling towards each other the corner sides of a frame and of gripping round objects markedly more firmly.
Another faculty brought by the invention also results from the movability of the arms along the cylindrical support part. Spreading with an assembleur of two reversed movable parts, each provided with an elastic buffer, between a surface and an auxiliary bar kept parallel to said surface makes possible to press at any place of this surface along this bar. An auxiliary bar, such as a ruler or a tool handle, can be kept parallel to a surface by the holders of two three-element vertical helping-hands of which the overlappers grip two opposite edges of said surface. There is no risk for the support part of damaging said surface if the movable part having its elastic buffer pressing the surface is slipped at one of the furthest ends of the support part since the last one does not go beyond said buffer. This kind of clamping has been called xe2x80x9ccovering clampingxe2x80x9d. Thus it is possible to press against a surface very far from its edges, provided the auxiliary bar would be large enough. In this way, the jaw depth of the movable parts is made potentially unlimited. And whatever the shape of the surface is plane, convex, concave or tortured, that is true. It is sufficient that the auxiliary bar more or less follows the outlines of the surface. For a stronger pressure, an overlapper might replace the assembler that has to be turned into a spreader. Until now this type of clamping by covering was not much familiar to persons having ordinary skill in the art, because traditional clamps could not generally be turned into spreaders and a spreader was a special tool rarely available in the workshops. In addition wedges are rather difficult to be used with a traditional spreader. According to the present invention, the covering clamping can be easily and directly executed with the very same assemblers as the ones which permit of making all the other above disclosed original arrangements, provided if needed with additional movable arms. It is the multipurpose characteristic of the new assembler.
Another worthwhile feature of the invention is that a ring buffer belonging to a clamping or spreading assembler can support against its side, under various angles, the pressure of a buffer belonging to a second assembler in clamping or spreading position. This feature results from that every elastic substance, which can go into such a buffer, is malleable and generally not slippery. Therefore the buffer of another movable arm of said second assembler can force against the side of an object even this last one has no other side parallel to said first side or against a buffer belonging to a third assembler, also in clamping or spreading position. Such a positioning permits to clamp even there is no outline easy to be seized, which is often the case of objects d""art to be restored. This positioning was so far very difficult to be achieved with traditional clamps because sizeable and crooked wedges had to be jammed under the jaws, said wedges being always uneasy to be put in and sometimes hard to be found out. Generally such a positioning was requiring more than two hands and was brutishly forcing whatever was the solidity of the objects to be clamped. This positioning turns to be elementary, even under a weak clamping force, with the new assembler, owing to the use of elastic ring buffers. It has been called angle clamping, staple clamping or bridge clamping, according to the number of assemblers, which are involved. For a firmer anchorage an overlapper might replace the supporting assembler.
The result of all the foregoing is that the assembler according to the invention is multipurpose and that its general process of use, which permits of holding a set of objects by clamping without damaging them, comprises the following steps:
positioning said set of objects between said arms,
sliding said at least one movable arm along said support part so as to apply the contact face of said elastic buffer against a respective surface of said set,
manually exerting pressure upon the backs of said arms in direction of said set. The force exerted by fingers or hand palms on said backs is more or less transmitted by translation against said set. This set of objects reacts and opposes a resistance, which rises with the exerted pressure and
stopping the exertion of pressure when hands feel enough resistance. Said at least one movable arm is then repulsed by said set. As a result, it tilts with respect to said support part, such that a frictional force is created between said support part and an interior surface of the transverse hole of said arm, thereby locking said arm in place with respect to said support part.
Other characteristics and advantages of the invention will be more apparent from the following detailed description in view of the attached drawings, upon which: